The impact of rhubarb polysaccharides on Toll-like receptor 4-mediated activation of macrophages

Objective: Toll-like receptor 4-mediated acute anterior uveitis is a serious ocular inflammatory disease, and new targeted drug therapy is the primary treatment The objective of the present study was to investigate the molecular mechanism responsible for the activation of macrophages by rhubarb polysaccharides (RP) and try to find a new treatment for TLR4 pathway-mediated acute anterior uveitis. Method: RAW264.7 macrophage cell lines were cultured in vitro, and rhubarb polysaccharides were used to stimulate the cell lines. An immunofluorescence technique was used to determine cell activation status by rhubarb polysaccharides; the ELISA technique was used to examine the production of cell supernatant inflammatory cytokines IL-1 beta, IFN-gamma, IL-6, and INF-alpha; and Western blot and real time RT-PCR were used to determine the effect of RP on TLR4, MyD88, and NP-kappa B p65 proteins and gene expression. Results: Using Western blot, real time RT-PCR, ELISA, and immunofluorescence techniques, we found that rhubarb polysaccharides in vitro could activate macrophages; induce TLR4, MyD88, and NF-kappa B p65 protein and gene expression; and also induce the production of cytokines IL-1 beta, IFN-gamma, IL-6, and TNF-alpha. Conclusion: The results presented in this report suggest that RP induce macrophage activation through the TLR4/NF-KB signaling pathway. Our data suggest that RP have the potential to be used for their immunostimulatory effect in the treatment of infectious diseases such as TLR4-mediated acute anterior uveitis. (C) 2013 Elsevier B.V. All rights reserved.